The present invention relates to a vehicle driving device.
Japanese Patent Application Publication No. JP-A-2004-353782 discloses a vehicle driving device, illustrated by FIG. 4, that includes a transmission mechanism and an electric motor. FIG. 4 is a side sectional view of a vehicle driving device 51 described in Japanese Patent Application Publication No. JP-A-2004-353782. The vehicle driving device 51 includes a damper device 53, a first motor generator 54, a power transfer mechanism 55 that includes a planetary gear mechanism, a second motor generator 56, and a transmission mechanism 57 that are sequentially disposed on an extension of a crank shaft 52 of an engine (not shown) and housed in a case 58. The transmission mechanism 57 includes a planetary gear mechanism with two brakes 57a and 57b for switching the transmission gear ratio by regulating the rotation of any element of the mechanism.
The case 58 includes a first case body 58a, a second case body 58b, and an end cover 58c that are listed in the order of their closeness to the crank shaft 52. The second case body 58b is formed integrally with an intermediate wall portion 59 extending inwardly in the radial direction of the second case body 58b from an inner circumferential wall thereof, and the second case body 58b is configured to have two parts partitioned by the intermediate wall portion 59. The second motor generator 56 is mounted in the second case body 58b by inserting it from one end (the left end in FIG. 4) of the second case body 58b in the axial direction thereof, and the transmission mechanism 57 is mounted in the second case body 58b by inserting it from the other end (the right end in FIG. 4) of the second case body 58b in the axial direction thereof. The end cover 58c is mounted on the other end of the second case body 58b such that it covers the transmission mechanism 57 mounted in the second case body 58b. Thus, an input shaft 57c of the transmission mechanism 57 is supported by a bearing part 59a provided on the intermediate wall portion 59, and an output shaft 57d of the same is supported by a bearing part 58c1 provided on the end cover 58c. The first case body 58a is mounted on a front side of the second case body 58b. The damper device 53, the first motor generator 54, and the power transfer mechanism 55 are mounted in the first body case 58a. 
An oil pan 60 and a hydraulic controller 61 are mounted on an outer wall of the second case body 58b on the bottom side thereof. The oil pan 60 has an axial length extending from the neighborhood of the one end of the second case body 58b to the neighborhood of the other end in accordance with the entire length of the second case body 58b, and the oil pan 60 is mounted to cover a substantial part of the bottom side of the second case body 58b. The hydraulic controller 61 is disposed in an oil chamber 62 surrounded by the oil pan 60 and an outer wall of the case 58. The hydraulic controller 61 supplies oil supplied from an oil pump 63 to the motor generators 54 and 56, the transmission mechanism 57, and so on to cool and lubricate them or to disengage and engage the brakes 57a and 57b through switching of each valve incorporated therein.